We have been spending between 2 and 3 months wintering along the Gulf in it with our 50 lb German Shorthair Pointer. My wife loves the kitchen space and that was a plus.
The negatives are:
1) I hate the awning. The angle supports are always in the way. If only they could be swung down to use as vertical poles instead. I may go to a vintage awning for the door side.
2) The bed in the 20' is only 48" and can get crowded on a hot or restless night. Cold nights are great. Would have liked a full size bed and lost the additional space elsewhere.
3) The aluminum next to the bed can get very cold on a cold night (I am adding carpeting to the wall to help this).
4) The TV cannot be pointed out the door to watch, nor removed to take outside.
5) I did not get outside speakers for the radio/CD player. This would be nice.
6) No awning on the side windows. May add because they would be very nice.
7) My wife would like a larger refrigerator which would fit if we didn't have a fixed TV.
8) Fantastic Fans...we have two. I love Fantastic Fans, but these are the fully automatic ones which seem to always be turned on the wrong mode opening or closing in the middle of the night, or while traveling. We had vent covers installed so we could leave them open even when traveling on hot days. This works well.
9) Fresh water tank only 20 gallons! I couldn't believe this! Way too small! Also, it is difficult to completely fill.
Oh well...whine, whine, whine. We still really enjoy it. We moved down from a 29 ft Hitchhiker II 5th wheel. Fuel savings is 3-5 MPG. We can take it into any National Forest campground. We can get into almost any fuel station and into almost any city street. It can also go onto lots of dirt roads on BLM lands.
There will always be room for improvements/changes on your new AS.